Assessing L2 phonemic acquisition: a normalisation-independent method?

International audienceThis paper aims at addressing the issues thatemerge when attempting to analyse the acquisitionof L2 vowels: studies usually embed vowels in thesame /hVd/ template (e.g. Hillenbrand [14], Fer-ragne [10], Clopper [9]) in order to reduce coartic-ulatory effects, and the number of occurrences ofeach vowel is carefully controlled in order to complywith normalization constraints (e.g. Lobanov [17]).However, such methods make it difficult to test thepredictions of SLA models that base phonemic ac-quisition on phonemic parameters only (Flege [11],Best [2],[3]). This study investigates the develop-ment of advanced French learners for the acquisi-tion of phonemic contrasts (/I-i:/and/U-u:/) in thelongitudinal DIDEROTLONGDALE[13] corpus. 15speakers (12 female & 3 male) were recorded inspontaneous interviews over a period of two years.To test whether the acquisitions of the/I-i:/and/U-u:/constrasts are similar, a metric, the Ratio of the(contrast) DIstance to the vowel space Convex Hull(RaDiCHull,/rÊd.Ik."h2l/), is explored with differ-ent normalizing procedures to measure learner inputas compared to native speakers of English (the refer-ence points are from Hillenbrand [14] for values inHz, and from Clopper [9] for values in Bark